// @(#)Stats.java   5/2003
// Copyright (c) 1998-2003, Distributed Real-time Computing Lab (DRCL) 
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 
// 1. Redistributions of source code must retain the above copyright notice,
//    this list of conditions and the following disclaimer. 
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution. 
// 3. Neither the name of "DRCL" nor the names of its contributors may be used
//    to endorse or promote products derived from this software without specific
//    prior written permission. 
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// 

package drcl.comp.lib;

import drcl.comp.*;
import drcl.data.*;

/**
 * Statistical components.  
 * Receiving Double or DoubleObj, outputing mean and std.
 */
public class Stats extends Component
{
  double sum = 0.0;
  double varsum = 0.0;
  long count = 0;
  boolean outenabled = false;
  Port outmean = addPort("mean", false);
  Port outstd = addPort("std", false);
  
  public Stats()
  { super(); }

  public Stats(String id_)
  { super(id_); }

  public double getMean()
  { return sum / count; }

  // ???
  public double getStd()
  {
    double mean_ = getMean();
    return Math.sqrt(varsum / count - mean_*mean_);
  }

  public boolean isOutputEnabled()
  { return outenabled; }

  public void setOutputEnabled(boolean enabled_)
  { outenabled = enabled_; }

  public void reset()
  {
    super.reset();
    sum = varsum = 0.0;
    count = 0;
  }
  
  public void duplicate(Object source_)
  {
    super.duplicate(source_);
    Stats that_ = (Stats) source_;
    outenabled = that_.outenabled;
  }

  public String info()
  {
    return " Mean = " + getMean() + "\n"
        + "  Std = " + getStd() + "\n"
        + "Count = " + count + "\n"
        + "Output Enabled: " + outenabled + "\n";
  }
  
  protected void process(Object data_, Port inPort_)
  {
    double v = data_ instanceof Double?
        ((Double)data_).doubleValue(): ((DoubleObj)data_).value;
    sum += v;
    varsum += v*v;
    count ++;

    if (outenabled) {
      double mean_ = sum / count;
      double std_ = Math.sqrt(varsum / count - mean_*mean_);
      outmean.doSending(new double[]{count, mean_});
      outstd.doSending(new double[]{count, std_});
    }
  }
}
